Endoscopic and/or laparoscopic devices for use in medical procedures typically are passed through a working channel of a suitable introduction sheath (such as, e.g., an endoscope or laparoscope) positioned in a body cavity in order to reach an operative site at a distal end of the sheath. For purposes of this description, “distal” refers to the end extending into a body and “proximal” refers to the end extending out of the body. The size of an end-effector on the distal end of the endoscopic device, such as, e.g., scissors, snares, forceps, stent delivery devices, biopsy needles, and electro-coagulation probes, therefore, maybe limited by the diameter of the introduction sheath's working channel.
For example, an endoscopic device may include an end-effector, such as, e.g., biopsy forceps, that typically consists of two jaw-like members located distally on an end of a long, flexible tube or sheath. The jaw members are operable to open and close, enabling the jaws to grasp and cut away tissue for biopsy sampling. In at least the closed position, the jaw members must be small enough to fit through the working channel of the endoscope, however, which limits the size of the tissue samples obtained. A 3 French (“Fr.”) forceps device that fits in a 7 Fr. ureteroscope acquires tissue samples that are often too small to be accurately evaluated. The size limitation of the jaws also prohibits the use of forceps for other applications, such as grasping gall stones and kidney stones or removing or displacing larger size tissue samples. A working channel of an endoscope that is sized to accommodate an endoscopic device with a larger profile or diameter can inhibit both the flexibility of the endoscope and/or the ability of the endoscope to house other functional components, such as visualization devices, or may increase the outer diameter of the endoscope to an unusable size.
Recent advances in endoscope technology have complicated the task in providing for sufficiently sized end-effectors. On one hand, endoscopes have been reduced in size, responding to the need to navigate through ever smaller bodily cavities. At the same time, endoscopes have become capable of carrying more endoscopic devices, so that endoscopes may be provided with a number of end-effectors, enabling deployment of a range of devices, such as an illumination device, a camera, a tissue resection device, and a tissue retrieval device, all carried in one or more working channels of the same endoscope. The possibility of so many devices being used simultaneously complicates the task of accommodating an oversized end-effector.
Therefore, a need exists for an improved apparatus and method for loading and using an end effector that cannot be inserted completely through the working channel of an endoscope.